PROJECT SUMMARY/ABSTRACT Overview: The goal of this study is to develop, refine, and test the feasibility and preliminary efficacy of a self- administered, mobile sexual dysfunction intervention application (app) in improving outcomes of hematopoietic stem cell transplant (HCT) survivors. Background: Sexual dysfunction is the most common complication post-HCT with over 40% of male and 60% of female survivors reporting long-term sexual dysfunction post-transplant. Importantly, sexual dysfunction is associated with worse quality of life (QOL), relationship dissatisfaction, and psychological distress, which further contributes to the morbidity in this population. HCT survivors experience a unique and wide range of biologic, interpersonal, psychological, and social factors that impact their sexual function. Given the multifactorial nature of sexual dysfunction, a multimodal approach is necessary to address patients? specific issues and concerns. Despite the increasing use of HCT and the burden of sexual dysfunction in this often young patient population, there are currently no interventions to address their sexual dysfunction. We completed a pilot study in which we recruited HCT survivors with sexual dysfunction causing distress to participate in a multimodal intervention that entailed monthly visits with trained study nurse practitioners. We demonstrated that the intervention was feasible and led to statistically and clinically significant improvements in patients? satisfaction and interest in sex, sexual health and function, QOL, and symptoms of depression and anxiety. Despite the success of our prior work, the majority of HCT survivors will not have access to clinicians with expertise to address their sexual dysfunction. Research Plan: We propose to adapt our sexual health intervention to a mobile app, which patients can self- administer via tablet computer to ensure the accessibility and scalability of the intervention. We recently secured funds to develop a multimodal mobile app to address sexual dysfunction in HCT survivors. The proposed R21 project will use mixed qualitative and quantitative methods to 1) refine the app based on an open pilot study with six HCT survivors experiencing sexual dysfunction and 2) conduct a pilot randomized controlled trial of the mobile app versus enhanced standard care in 80 HCT survivors to assess the feasibility and preliminary efficacy of the mobile app in improving patient-reported sexual function, QOL, and mood. Environment: This project will be conducted at the Massachusetts General Hospital (MGH) Cancer Center, which cares for over 1000 HCT survivors and conducts over 200 transplants per year. Dr. El-Jawahri will collab- orate with a nationally recognized team of researchers in supportive and palliative care research, behavioral intervention development, engineering, and sexual health. Relevance of Research: This project will test an innovative, patient-centered, mobile app that will substantially enhance the care of HCT survivors and has the potential for easy dissemination and wide utilization.